73 replies to this topic

[masssrt]

can't wait for results

[aco]

I have never modified my exhaust. This may be a stupid question, but why are high flow cats "off road use only"? If the catalytic converters are present, couldn't they still pass emissions testing?

[olyar15]

aco, on Apr 2 2008, 05:34 AM, said:

I have never modified my exhaust. This may be a stupid question, but why are high flow cats "off road use only"? If the catalytic converters are present, couldn't they still pass emissions testing?

I believe there are regulations regarding cat replacement. Also, my experience with high-flow cats on a 300ZX showed that they had a lot of trouble passing exhaust emission levels.

[Scotts-GTR]

I am favorite this.

[the King]

I will take one cracked ECU please.
Cost? JDM GT-R for the Caribbean(Jamaica)= shipping and handling included?

[yacoub]

yes, "off-road" status is related to emissions primarily, though it can also be related to noise levels.
exciting to see the ECU cracked already. that's a good sign of things to come!

[Arch5]

"off-road use only" is also a way the manufacturer can avoid the hassels of getting things DOT approved and leave all the liability for fines on the consumer. You'll see quite a few after market items stamped "off-road use only."


BTW...great job Cobb!!!! Those look like they'll flow MUCH better than those stock stuffed burritos. Should see some great gains since it's for a turbo application. My 350z gained ~9hp by putting a set of high-flow cats on.

Question: Are you guys replacing all 4 cats, or are you deleting two with this set-up?

Edited by Arch5, 02 April 2008 - 01:53 PM.

[MAXXSTEEL]

looks promising

[Fast GTR]

SO lets say I get caught with these on by the police one day.

I live in California, what type of problems might arise for me?

Edited by Fast GTR, 02 April 2008 - 03:51 PM.

[masssrt]

So if you take it 'off road', that will have less of an impact on the environment I suppose?

[GranTuRismo]

Fast GTR, on Apr 2 2008, 11:58 AM, said:

SO lets say I get caught wiht these on by the police one day.

I live in California, what type of problems might arise for me?

Most likely you will get fined and/or have to provide proof of correction back to stock via inspection. Depends on the cop, I too live in CA and have heard some horror stories on savvy police coming down on modded cars.

[ShahulX]

they would never know unless you had no cats and were spitting soot and black smoke....

I'd like 2 high flow cats, dismiss the other 2 ... And a full titanium form there back

Thanks Cobb, go American tuners!!

[timechaser]

Impressive!

Now - who can tell me how to get in touch these boys at Cobb Tuning. I am in Singapore and a bunch of us are immensely interested in getting our hands on the AccessPORTs...

Of course we have a bunch of other questions as well about the JDM cars which our Japanese brethren are wholly unprepared to answer!

Chuck - or whoever has contact details. Please PM me if you dont want to put up on the board. I am serious about this question.

[ShahulX]

just google Cobb tuning... They are pretty east to get ahold of... If I could post links from my iPhone I'd do it for you

[the King]

I'll take the Mine's cat. It maybe a bit more street legal. Cobbs is closer home so I am very interested in that cracking sound I hear.

[Trey@COBB]

Thanks for the support guys!

On the 'off road use' issue, the situation is that it is simply illegal for you to replace ANY of the factory emissions equipment on a new car. Even if you are beyond the year/mileage limits of the regulation, you still have to replace with a certified OBD-II cat which currently don't officially exist in the US.

So while the emissions output will be very close to stock and even if you still pass the emissions 'sniffer' test, to the letter of the law it is not a legal modification. This is the same if you buy our cats, Mine's, or anyone elses OTHER THAN stock Nissan. To be honest, to the letter of the law even if you REDUCE emissions from what the stock car produced it would still not be technically legal because the law doesn't just state the car has to pass emissions testing but also that you cannot alter the factory emissions equipment. That includes altering it in a manner that may improve it. Silly, I know, but those are the laws. There are certification processes you can go through, as we are doing with the intakes, but currently for the catalytic converters there are no approved solutions for OBD-II cars.

So anything we offer that may alter the emissions equipment on the vehicle has to be used by off-road racing vehicles only. If you're in California (or really anywhere in the US), don't touch those items if you're planning on driving your car on public roads and you'll be legal. There are a LOT of guys contacting us already that only plan on track driving their GT-Rs, which is why we developed this part.

The 'cat-back' section is open from an EPA point-of-view but there are still other laws that must be met such as the SAE J1169 mandated sound requirements (95 dB) and some other safety related requirements. The also applies to other countries as well. The ADR in Australia, Japan is getting much more strict particularly with exhaust modifications, you have the various laws in the EU and in particular the very tough TUV in Germany. That's not to say the aftermarket will go away, but we have to be more professional about the way we operate. Simple as that.

If anyone has any specific questions for me in particular about the GT-R, feel free to post here or email me directly at trey (at) cobbtuning.com. I'm doing part of the GT-R ECU discovery and tuning so I'm happy to answer any technical questions you have. I don't know everything, obviously, but I'm happy to share with others what I know.

Cheers,
Trey @ COBB

[MindlessOath]

trey. what do you think about using MOTEC ecu replacement? or even the Greddy E-Manage Ultimate?
do you think they would be great solutions for the GT-R? or are you just not there yet.

also. i know past nissans had to replace the whole ECU to tune it. (actually modify the ecu chips internaly itself). how will accessPort play a roll if thats the the thing here?

are you actually able to write to the ECU using accessport?

[aco]

Thank you Trey for the very clear answer to my "off road use" question. As I am not in the first year allocation market, I have yet to decide if this will be a track only car.

[yacoub]

ShahulX, on Apr 2 2008, 05:53 PM, said:

they would never know unless you had no cats and were spitting soot and black smoke flames....

:D

[Trey@COBB]

MindlessOath, on Apr 3 2008, 01:24 PM, said:

trey. what do you think about using MOTEC ecu replacement? or even the Greddy E-Manage Ultimate?
do you think they would be great solutions for the GT-R? or are you just not there yet.

I won't comment on the capabilities of other products, all I will say is that the factory ECU is a very capable system. You get very advanced closed loop boost control, electronic throttle body (plural as there are two) control with feedback between the two to keep them 'in-sync' in one another, variable cam timing control, etc. Add to that all the communications that happen between the seperate computers on the car through the CAN BUS (traction control, transmission control, ABS, etc) plus the fact that it is OBD-II compliant. That all is just the tip of the iceberg, but I hope the reason for my opinion is understood.

I know from dealing with other ECUs, particularly the latest model ones we're seeing from Nissan, Mazda, Subaru, Toyota, etc that the degree to which they are controlling things is very difficult to consistently manipulate unless you can get inside it and actually change it like a Nissan engineer would have.

MindlessOath, on Apr 3 2008, 01:24 PM, said:

also. i know past nissans had to replace the whole ECU to tune it. (actually modify the ecu chips internaly itself). how will accessPort play a roll if thats the the thing here?

are you actually able to write to the ECU using accessport?

You don't need to replace any chips on the GT-R ECU to tune it. It uses a sophisticated 32-bit processor w/ on-board FLASH memory to store all its program code and calibration data. With the AccessPORT, we can write new data to the ECU. This is much like how Nissan would do it to make an update to the ECU software to address a driveability issue or the like.

The AccessPORT installation process works as follows:
1) AccessPORT is plugged into factory OBD-II connector and powers itself on.
2) You then select which 'map' you want to use based on your engine modifications (ie: stock, exhaust, exhaust+intakes, etc)
3) The AccessPORT will first read the stock data from the ECU (ALL of it) and save it, then it will re-write the ECU with our new tuned data.
4) Done. Easy as that.

If you want to change a map (say you upgraded the car with new exhaust) you just go to Change Map on the AccessPORT, select the new map and it'll flash it straight to the ECU. If you want to uninstall the AccessPORT, you can do so and it'll return the ECU programming 100% back to stock. The AccessPORT can then be installed to another GT-R, or back on your own GT-R. You can install and uninstall it as many times as you'd like. Some of our other customers do this action when they go into the Dealer for service work.

It's also worth noting that the AccessPORT only works on one vehicle at a time. Also, the dealership service tools (ie: Consult-III) still work 100% with the AccessPORT installed except their ability to update the ECU with new software (reflash it). We don't want customers losing their ECU tunes by the dealership accidently writing over it so we lock out that ability. To unlock it, and allow the dealer to rewrite the ECU, all you have to do is Uninstall the AccessPORT first. Again remember you can do this as often as you want.

The core concept of the AccessPORT is simply to give enthusiasts the convenience of reflashing the ECU when THEY want do. No more shipping ECUs back and forth whenever tunes are improved, changes are made to the car, or worse case the dealership erases it and VERY worse case you have to pay to get it reflashed again.

Hope that helps,
Trey @ COBB